1. Field of the Invention
The present invention relates to a small and thin motor, a stator for the motor, and a method of manufacturing the same.
2. Description of Related Art
A motor and a stator for the motor in the related art will be described with reference to FIGS. 9 to 13.
FIG. 9 is a sectional view of a conventional motor. FIG. 10 is a plan view of a stator assembled in the motor shown in FIG. 9. FIG. 11 is a plan view of other conventional stator. FIG. 12 is a perspective view of part of a core member of the stator shown in FIG. 11. FIG. 13 is a plan view of the core member shown in FIG. 12 with windings.
The conventional motor will now be described with reference to FIGS. 9 and 10. A motor 10 is an outer rotor type motor including a stator 20, a rotor 30, and a rotating shaft 40.
The stator 20 is constituted by a flat ring-shaped housing 21 made from a magnetic steel plate, and a doughnut-shaped laminate core 24 as shown in FIG. 10. The housing 21 has an inner peripheral wall 22 and an outer peripheral wall 23. The outer peripheral portion of the laminate core 24 is divided by six slits 25 into six sections, winding spaces 26 are provided in their respective middle portions, and coils 27 are wound around the winding spaces 26, respectively. The stator 20 has a structure in which the laminate core 24 is press-inserted into the inner peripheral wall 22, and then adhesively bonded.
The rotor 30 is constituted by a cylindrical rotor case 31 and a magnet 33 for rotary drive. The magnet 33 is secured to the inside face of an outer peripheral wall 32 of the rotor case 31. The rotor case 31 is supported at the center portion by the rotating shaft 40. The outer peripheral wall 32 of the rotor case 31 and the magnet 33 are disposed such that they are positioned between the outer peripheral portion of the laminate core 24 and the outer peripheral wall 23 of the housing 21.
The rotating shaft 40 is supported so as to be rotatable by a fluid dynamic bearing 41 and a thrust bearing 42 in the interior of an inside diameter side cylindrical portion 22 of the housing 21.
Therefore, the motor 1 rotates by transmitting rotating torque obtainable from the magnet 33 and the outer periphery of the laminate core 24 via the rotor case 31 to the rotating shaft 40.
If the outside diameter of the motor 10 so configured is reduced with the aim of miniaturization, the winding spaces 26 diminish and, in addition, there occurs difficulty in the work of winding the coils 27 through a width W of the narrow slits 25, which is, for example, approximately 0.3 mm.
For instance, Japanese Patent Application Publication No. 2003-9444 (page 5, and FIG. 4) discloses the stator shown in FIG. 11, as one structure of a motor for solving the coil winding work problem encountered in miniaturizing the motor 10. A stator core 50 is divided into a plurality of core members 51 as shown in FIG. 12, nine of these core members being shown in FIG. 11.
The manufacture of the stator core 50 includes the step in which the core members 51 are prepared separately, a coil 53 is previously wound around a body portion 52 of each of the core members 51, and these core members 51 are arranged in a ring-shape by fitting and bonding their adjacent end faces to each other.